Alexander Agassiz, 1835-1910

Biography with photograph

Letter and Recollections of Alexander Agassiz: The 1891 Albatross Expedition

Presented here is another in the list of historic accounts of iconic research cruises of the USFC Steamer Albatross, this a reminiscence of the renowned scientist Alexander Agassiz edited by his son G. R. Agassiz, a chapter from the volume “Letters and Recollections of Alexander Agassiz,” published in 1913. Agassiz made three major cruises in the Albatross in 1891, 1899–1900, and 1904–05, adding greatly to the world’s store of specimens and knowledge of thalasography, his favored term for oceangraphy, and specifically of the Pacific Ocean. Having made important cruises and studies with the Blake in the Caribbean, he sought to do comparable research in the Pacific. His opportunity came in 1890, and with the consent of President Benjamin Harrison, he took charge of this Albatross research cruise, paying much of the expense himself. In contrast with the other ships he had been on, he found the laboratories, equipment, and furnishings to be comparatively luxurious and extremely well appointed for his work. Further, the Albatross was then captained by Lieutenant Commander Zera Luther Tanner who seemed to take as much interest in the oceanographic research as did the scientists, and Agassiz appreciated working with him, too. Little of the original text has been altered, and readers are cautioned that some of the views expressed may reflect unfortunate prejudices of that era toward individuals, nationalities, etc.

Life history of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) (Richardson, 1836) off the southeastern United States

The life history of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) was described from 1093 specimens collected from Virginia to northern Florida between April 1997 and March 1999. Longitudinally sectioned vertebral centra were used to age each specimen, and the periodicity of circuli deposition was verified through marginal increment analysis and focus-to-increment frequency distributions. Rhizoprionodon terraenovae reached a maximum size of 828 mm precaudal length (PCL) and a maximum age of 11+ years. Mean back-calculated lengths-at-age ranged from 445 mm PCL at age one to 785 mm PCL at age ten for females, and 448 mm PCL at age one to 747 mm PCL at age nine for males. Observed lengthat-age data (estimated to 0.1 year) yielded the following von Bertalanffy parameters estimates: L∞= 749 mm PCL (SE=4.60), K = 0.49 (SE=0.020), and t0= –0.94 (SE=0.046) for females; and L∞= 745 mm PCL (SE = 5.93), K = 0.50 (SE=0.024), and t0= –0.91 (SE = 0.052) for males. Sexual maturity was reached at age three and 611 mm PCL for females, and age three and 615 mm PCL for males. Rhizoprionodon terraenovae reproduced annually and had a gestation period of approximately 11 months. Litter size ranged from one to eight (mean=3.85) embyros, and increased with female PCL.

A new species of Henneguya (Myxosporida, Protozoa) from West African catfish, Clarias lazera Val., with a review of the genus Henneguya Thelohan, 1892

A new species of myxosporida, Henneguya clariae, is described from the gills of Claria���s Iazera caught from various waters in Nigeria. Pathogenic effects in the destruction of the components of the branchial system are about 25% of Clarias lazera. A review of the genera Henneguya myxobilatus, and Neohenneguya is made and these were synonymised, with some reservations in the case of to Henneguya. A checklist of the genus Henneguya is given.